In recent years, it has become practical to use a high-speed cellular radio communication technique, such as LTE (Long Term Evolution), WiMAX, etc., and therefore, the communication rate of radio communications services enjoyable for mobile users has been significantly improved. Moreover, it is expected that the introduction of the fourth-generation cellular radio communication technique, such as LTE-A (LTE-Advanced) etc., would further improve the communication rate.
On the other hand, there has been a rapidly increasing number of mobile users, and therefore, there has been increasing use of applications requiring a high data rate. As a result, the cellular radio communication technique has not yet been developed to meet all needs of mobile users. A solution to meet various needs of mobile users is to utilize an MVNO (Mobile Virtual Network Operator). An MVNO refers to a provider which borrows a physical network infrastructure from an MNO (Mobile Network Operator) to provide radio communications services. In such a service scheme, MVNOs do not need to pay the high cost of construction of a physical network. An MNO lends a physical network to an MVNO and allows the MVNO to use a portion of the radio resources, thereby receiving a usage charge while effectively utilizing the facility. As the number of available MVNOs increases, a wider choice of services can be provided, which is of great benefit to end users.
A problem which occurs when MVNOs are utilized is congestion on radio resources. If a large number of providers provide radio communications services on limited radio resources without control, radio signals are likely to interfere with each other, leading to a deterioration in general communication performance or quality. Therefore, providers which provide radio communications services are required to use radio resources with as much efficiency and cooperation as possible.
A variety of techniques are known for efficiently using limited radio resources while avoiding interference. For example, Patent Literature 1 below proposes a technique of controlling transmission power between radio communications services in a cooperative manner. Patent Literature 2 below proposes a technique of controlling transmission beams between radio communications services in a cooperative manner.